This invention relates generally to swath printing, and more particularly to inkjet printers using separate nozzle arrays for each different color ink.
While much research and development has been directed toward increasing the nozzle resolution on inkjet printheads as the best way to improve print quality, some benefits can also be obtained through print mode techniques. Higher resolution addressability has already been obtained to some degree with monochrome print mode techniques. Examples of this are found in U.S. Pat. No. 5,541,625 issued Jul. 30, 1996 for METHOD FOR INCREASED PRINT RESOLUTION IN THE CARRIAGE SCAN AXIS OF AN INKJET PRINTER; U.S. Pat. No. 5,469,198 issued Nov. 21, 1995 entitles MULTIPLE PASS PRINTING FOR ACHIEVING INCREASED PRINT RESOLUTION; and U.S. Pat. No. 5,535,307 issued Jul. 9, 1996 entitled PRINTING OF VARIABLE DOT SIZES DEPENDENT UPON IMAGE DENSITY FOR IMPROVED GRAPHICS.
The monochrome techniques for increased addressable resolution, and the related depletion techniques, are not easy to apply to color printing, particularly where the goal is to have increased resolution in both the X and Y axes (media advance and carriage scan axes, respectively) as generally labeled for wide format printers/plotters.
An increased color resolution printer from Epson was introduced which provided some color depletion after increasing addressable resolution to 720.times.720. This product was unfortunately based on a very low nozzle resolution printhead of 90 dpi, which required a slow tedious eight pass print mode as well as special media to decrease ink dot gain.
So there still remains a need for a faster increased resolution higher resolution print technique which includes improved dot depletion to assure better print quality for a wider selection of media.